Occasionally connected application - SQL Compact+EntityFramework+SyncFramework issue

Question

I'm currently exploring different avenues for a new application that falls in the "occasionally connected" category. After some research I "decided" to go for a central SQLServer and clients with SqlCompact database that would sync when required/possible.

When "connecting" everything together I ended up with the following exception.

[A]System.Data.SqlServerCe.SqlCeConnection cannot be cast to 
[B]System.Data.SqlServerCe.SqlCeConnection. 
Type A originates from 'System.Data.SqlServerCe, Version=4.0.0.0, Culture=neutral, PublicKeyToken=89845dcd8080cc91' in the context 'Default' 
at location 'C:\Windows\assembly\GAC_MSIL\System.Data.SqlServerCe\4.0.0.0__89845dcd8080cc91\System.Data.SqlServerCe.dll'. 
Type B originates from 'System.Data.SqlServerCe, Version=3.5.1.0, Culture=neutral, PublicKeyToken=89845dcd8080cc91' in the context 'Default' 
at location 'C:\Windows\assembly\GAC_MSIL\System.Data.SqlServerCe\3.5.1.0__89845dcd8080cc91\System.Data.SqlServerCe.dll'.

Further reading helped me realize that Sync Framework did not support SqlServerCe v4.0, which make it incompatible with EntityFramework.

I am now wondering if the road I'm about to take is the right one. Any alternative solutions or workaround would be appreciated.

Some further informations that might be pertinent:

• Number of clients ~100
• Number of clients that will be allowed to sync both way (update central server) ~10
• Database is quite small (20MB) with little growth expected.

Answer 1

you can actually get it working with SQL CE 4, it's an unsupported one though.

see: SYNC FRAMEWORK AND SQL COMPACT 4 (YES, YOU CAN!)